01 BFS.cpp

/**

Complexity : O(V+E)

**/

/**Which of the favors of your Lord will you deny ?**/

#include<bits/stdc++.h>
using namespace std;

#define LL long long
#define PII pair<int,int>
#define PLL pair<LL,LL>
#define MP make_pair
#define F first
#define S second
#define INF INT_MAX

#define ALL(x) (x).begin(), (x).end()
#define DBG(x) cerr << __LINE__ << " says: " << #x << " = " << (x) << endl

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class TIn>
using indexed_set = tree<
                    TIn, null_type, less<TIn>,
                    rb_tree_tag, tree_order_statistics_node_update>;

/*
PBDS
-------------------------------------------------
1) insert(value)
2) erase(value)
3) order_of_key(value) // 0 based indexing
4) *find_by_order(position) // 0 based indexing

*/

inline void optimizeIO()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}

const int nmax = 2e5+7;
const LL LINF = 1e17;

string to_str(LL x)
{
    stringstream ss;
    ss<<x;
    return ss.str();
}

//bool cmp(const PII &A,const PII &B)
//{
//
//}

vector<int>adj[nmax];
vector<bool>vis(nmax,false);
vector<int>dist(nmax,0);

void bfs(int s)
{
    queue<int>q;
    vis[s] = true;
    dist[s] = 0;
    q.push(s);

    while(!q.empty())
    {
        int now = q.front();
        q.pop();

        cout<<now<<" ";

        for(int next:adj[now])
        {
            if(!vis[next])
            {
                vis[next] = true;
                dist[next] = dist[now] + 1;
                q.push(next);
            }
        }
    }

    cout<<endl;
}

int main()
{
    optimizeIO();

    int n,m;
    cin>>n>>m;

    for(int i=0;i<m;i++)
    {
        int a,b;
        cin>>a>>b;

        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    while(true)
    {
        int v;
        cin>>v;
        bfs(v);
    }



    return 0;
}